Editing Openai/680a25f8-9f18-8004-a42d-cd36374ba000 (section)

==== ### ====

Conduction and convection are negligible for small particles at high altitude:
* Air density at 10 km is low (~0.4 kg/m³).
* Heat transfer to/from the air is modeled by: Pcond=hA(Tparticle−Tair)P_{\text{cond}} = h A (T_{\text{particle}} - T_{\text{air}})Pcond=hA(Tparticle−Tair) Where h∼10 W/m2⋅Kh \sim 10 \, \text{W/m}^2\cdot\text{K}h∼10W/m2⋅K at best.

For our crystal:
* Area = 1.26×10−9 m21.26 \times 10^{-9} \, \text{m}^21.26×10−9m2
* So even with ΔT = 10 K: Pcond≈10⋅1.26×10−9⋅10=1.26×10−7 WP_{\text{cond}} \approx 10 \cdot 1.26 \times 10^{-9} \cdot 10 = 1.26 \times 10^{-7} \, \text{W}Pcond≈10⋅1.26×10−9⋅10=1.26×10−7W

That’s comparable to radiative and latent processes — not dominant.

But here's the kicker:

🔹 Conduction and convection flow from the surrounding air to the particle.
🔹 The air is also cold and in sunlight — it doesn’t magically stay fixed at 223 K while particles are heating.

✅ These pathways do not short-circuit the solar heating process.
✅ And they do not prevent sublimation, because they don’t keep the crystal cold enough.